1. Field of the Invention
The present invention relates to a drying machine including an accommodating chamber in which things to be dried are accommodated and in which drying of the things to be dried is executed.
2. Description of the Related Art
In a drying machine, an electric heater or a gas combustor has heretofore been used as a heat source. After heating outside air by the electric heater or the gas combustor to obtain high-temperature air, the air is blown into an accommodating chamber in which things to be dried, such as clothes, are accommodated, and the things to be dried in the accommodating chamber are dried. Moreover, the high-temperature air in the accommodating chamber, by which the things to be dried have been dried, is exhausted to the outside.
However, in the drying machine in which the electric heater, the gas combustor or the like is used, outside air outside the accommodating chamber is used in the high-temperature air blown into the accommodating chamber, and therefore there is a problem that a drying time largely change by conditions of the outside air. High-temperature/humidity air which has come out of the accommodating chamber is exhausted to the outside, and therefore a problem has also occurred that temperature or humidity of a place where the drying machine is installed rises.
To solve the problem, a clothes drying machine has also been developed in which a heating pump constituted of a compressor, a heating coil, an expansion valve, and a cooling coil and capable of circulating a heat exchange medium, the things to be dried are dried by the high-temperature air heated by the heating coil, and moisture evaporated from the dried things is coagulated and discarded by the cooling coil (see, for example, Japanese Patent Application Laid-Open No. 11-99299).
By the use of the heating pump, it can be expected that a time required for drying the things to be dried is shortened and energy efficiency is raised, but there has been an earnest demand for further reduction of the drying time.
On the other hand, in the drying machine on which this type of the heating pump is mounted, a circulation direction of a refrigerant flowing in heat exchangers such as a heating coil and a cooling coil and a circulation direction of air which exchanges heat with the refrigerant have not been especially studied in the present situation.